Cloning and analysis of the envelope protein clone of HIV-1, CHNHLJ03009c34 from an infected individual in Heilongjiang province

摘要

To analyze the variability and phenotype of envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) prevalent in Heilongjiang province, cloning of the full-length env gene from the peripheral blood mononuclear cells (PBMCs) of an HIV-1 positive individual in Heilongjiang province in China was performed by using conserved region primers. The amplified PCR products were cloned into a plasmid vector and sequenced. Phylogenetic analysis was done upon the full-length Env amino acid sequence. Subsequently, an HIV-1 pseudotyped virus bearing the envelope protein was constructed and the infectivity was examined using U87 cell lines expressing CD4 with either CCR5 or CXCR4. As the result, two functional env clones named as CHNHLJ03009c34 (GenBank Accession No: AY905493) and CHNHLJ03009c33 were obtained. It was found that the homology between CHNHLJ03009c34 and an HIV-1 subtype B′ strain, RL42, isolated from Yunnan province, was 91.52% through comparing and analyzing full-length Env amino acid sequence of HIV-1 isolated from either China or abroad. Phylogenetic analysis indicated that CHNHLJ03009c34 has the closest molecular relation with strain RL42 based on analyzing the full-length of the Env, while it became an independent branch upon analyzing the sequences of C2-V3 region of the Env. The secondary structure analysis of the envelope protein showed that the antigenicity and hydrophobicity of the strain demonstrated have no definite difference from that of RL42. Examination of infectivity showed that pseudovirus CHNHLJ03009c34 could only infect U87.CD4.CCR5 cells, indicating that it was a R5-tropic HIV-1. In the conclusion, two HIV-1 env clones from an infected individual in Heilongjiang province have been identified as subtype B′ and R5-tropic HIV-1. This is the first report on the analysis of primary isolates in Heilongjiang province.